论文标题
简化方法的磁性蓝色移位方法
Simplified approach to the magnetic blue shift of Mott gaps
论文作者
论文摘要
降低温度后，莫特绝缘子中的抗铁磁有序伴随着单粒子光谱重量向较低能量的转移，以及将莫特间隙转移到较高的能量（磁性蓝色移位，MBS）。 MBS受双重交换和交换机制的约束。两种机制都在增加轨道数量时增强了MBS。通过对数值动力学平均场理论数据进行多项式拟合，我们为MBS提供了在跳跃和交换原型Hubbard-Kondo-Heisenberg模型方面的扩展，并讨论如何将结果推广到现实的Mott Mott或Charge-Charge-Mott或Charge-Charge-trans-Transfer-Transferrator材料。这允许以一种极为简单的方式估算真实材料中电荷差距的MB，以避免进行广泛的理论计算。该方法典型地应用于$α$ -MNTE，NIO和Bifeo $ _3 $，MBS约为$ 130 $ MEV，$ 360 $ MEV和$ 157 $ MEV。将值与以前的理论计算和可用的实验数据进行比较。我们的MBS的现成公式简化了未来的研究，搜索材料，在抗铁磁有序和电荷激发之间具有很强的耦合，这对于实现在femtosecentsecent Time量表上实现耦合的旋转旋转相干动力学而言至关重要。
The antiferromagnetic ordering in Mott insulators upon lowering the temperature is accompanied by a transfer of the single-particle spectral weight to lower energies and a shift of the Mott gap to higher energies (magnetic blue shift, MBS). The MBS is governed by the double exchange and the exchange mechanisms. Both mechanisms enhance the MBS upon increasing the number of orbitals. By performing a polynomial fit to numerical dynamical mean-field theory data we provide an expansion for the MBS in terms of hopping and exchange coupling of a prototype Hubbard-Kondo-Heisenberg model and discuss how the results can be generalized for application to realistic Mott or charge-transfer insulator materials. This allows estimating the MBS of the charge gap in real materials in an extremely simple way avoiding extensive theoretical calculations. The approach is exemplarily applied to $α$-MnTe, NiO, and BiFeO$_3$ and an MBS of about $130$ meV, $360$ meV, and $157$ meV is found, respectively. The values are compared with the previous theoretical calculations and the available experimental data. Our ready-to-use formula for the MBS simplifies the future studies searching for materials with a strong coupling between the antiferromagnetic ordering and the charge excitations, which is paramount to realize a coupled spin-charge coherent dynamics at a femtosecond time scale.
